The subject matter disclosed herein relates generally to nuclear medicine (NM) imaging, and more particularly to methods and systems for determining a location of a lesion detected by NM imaging within a volume of space.
Various imaging techniques have been used for detection of cancerous lesions within a region of interest. For instance, mammography is the most common imaging technique used to detect lesions within breast tissue. If a lesion is suspected as being cancerous from a mammogram, a biopsy may be performed in which a sample of the lesion is extracted from the breast tissue using a biopsy needle. In many cases, an additional imaging modality, such as ultrasound, may be used to guide the biopsy needle toward the lesion and verify that an end of the biopsy needle is within the lesion.
For some individuals, such as those who have dense breast tissue or who have had prior surgery, mammograms alone may not be capable of sufficiently detecting lesions. One alternative for such individuals may be molecular breast imaging (MBI), which is also referred to as breast-specific gamma imaging (BGSI). MBI uses a dual-head gamma camera system to image the breast. During an MBI session, a radiopharmaceutical (e.g., Tc-99m sestamibi or other agent) is injected into the patient and absorbed by lesions existing within the breast. The breast is then positioned within a space between two nuclear medicine (NM) cameras. The NM cameras detect gamma radiation emitted by the radiopharmaceutical within the lesion(s).
MBI typically provides two-dimensional (2D) images of the breast tissue. A 2D location (e.g., X, Y coordinates) of the lesion may be identified using the 2D images, but a depth (e.g., Z coordinate) of the lesion within the breast tissue may not be determined by the 2D images. When the depth of the lesion is unknown, guidance of the biopsy needle may be difficult and the risk of missing the lesion with the needle is increased. As a result, it may be necessary to acquire a large number of samples, thereby causing pain and discomfort to the patient and increasing a duration of the biopsy procedure. To improve guidance, some biopsy procedures utilize an additional imaging device, such as an ultrasound probe, but such devices can be expensive and can further complicate the biopsy procedure for extracting the sample.
Accordingly, there is a need for additional NM imaging systems, assemblies, and methods of locating lesions within patient tissue and/or extracting samples from the lesions in the patient tissue.